﻿using Serialize.Library;
using System;
using System.Collections.Generic;
using System.IO;

namespace Sql.DataBase
{
    /// <summary>
    /// 数据库配置操作对象
    /// </summary>
    public class DatabaseManager
    {
        #region 变量
        /// <summary>
        /// 数据库配置文件路径
        /// </summary>
        private static string databaseConfigPath;

        /// <summary>
        /// 数据库实例配置
        /// </summary>
        private static Dictionary<string, DatabaseInstance> databaseInstanceDictionary;

        /// <summary>
        /// 侦听文件系统对象
        /// </summary>
        private static FileSystemWatcher sWatcher = new FileSystemWatcher()
        {
            NotifyFilter = NotifyFilters.CreationTime | NotifyFilters.LastWrite
        };

        /// <summary>
        /// 同步锁对象
        /// </summary>
        private static readonly object locker = new object();

        /// <summary>
        /// 数据库配置文件
        /// </summary>
        private const string dbConfigFilePath = @"DataBaseConfig\Database.config";
        #endregion

        static DatabaseManager()
        {
            try
            {
                string rootDic = string.Empty;

                try
                {
                    rootDic = AppContext.BaseDirectory;
                }
                catch
                {
                    rootDic = AppDomain.CurrentDomain.BaseDirectory;
                }
                databaseConfigPath = $"{rootDic}{dbConfigFilePath}";
                sWatcher.Changed += (s, e) => { InitDatabaseList(); };
                sWatcher.Path = Path.GetDirectoryName(databaseConfigPath);
                InitDatabaseList();
                sWatcher.EnableRaisingEvents = true;
            }
            catch (Exception ex)
            {
                throw ex;
            }
        }

        /// <summary>
        /// 获取数据库配置实例
        /// </summary>
        /// <param name="name"></param>
        /// <returns>处理结果</returns>
        public static DatabaseInstance GetDatabase(string name)
        {
            return databaseInstanceDictionary[name];
        }

        /// <summary>
        /// 初始化数据库配置集合
        /// </summary>
        private static void InitDatabaseList()
        {
            lock (locker)
            {
                try
                {
                    databaseInstanceDictionary = new Dictionary<string, DatabaseInstance>();
                    Databases databases = XmlHelper.XmlToObject<Databases>(databaseConfigPath);
                    foreach (DatabaseGroup group in databases.GroupList)
                    {
                        foreach (DatabaseInstance instance in group.InstanceList)
                        {
                            databaseInstanceDictionary.Add(instance.Name, instance);
                        }
                    }
                }
                catch (Exception ex)
                {
                    throw ex;
                }
            }
        }
    }
}
